As a broadband optical access technology, a Passive Optical Network (PON) adopts a point-to-multipoint topology structure. The PON is formed by an Optical Line Terminal (OLT), an Optical Distribution Network (ODN), and one or more Optical Network Units (ONUs) or Optical Network Terminals (ONTs). The OLT is located at a central office, and is not only a switch or router, but also a multi-service providing platform; the OLT can provide various wide area network interfaces, can further provide a plurality of Gigabit Ethernet interfaces and 10-Gigabit Ethernet interfaces, and can also provide switching and routing functions of Layer 2 and Layer 3. The ONU or ONT is located at a user side, and the difference between the ONU and the ONT lies in that the ONT is directly located at a user end, while other networks such as the Ethernet are further located between the ONU and a user; the ONU or ONT can provide various service interfaces, so as to realize user integrated access; and the main function of the ONU or ONT is to receive an optical signal and convert the signal into a form required by a client, such as Ethernet, Internet Protocol (IP) multicast, and T1 (a communication line with a transmission rate up to 1.544 Mb/s). The ODN is formed by passive apparatuses such as a splitter or coupler, and is connected to one OLT and one or more ONUs or ONTs in a passive manner. A PON protocol at least includes a PON data link layer and a PON physical layer, and a Protocol Data Unit (PDU) of the PON data link layer is referred to as a data link layer frame of the PON.
With the increase of broadband services, PON technologies are also evolving continuously, from an Asynchronous Transfer Mode (ATM) PON and a Broadband PON (BPON) to an Ethernet PON (EPON) and a Gigabit PON (GPON). In the GPON which generally bears Ethernet data only, after the PON is terminated on the OLT, the OLT extracts the Ethernet data, and maps user side data into a Multiprotocol Label Switching (MPLS) tunnel according to Ethernet characteristics in the extracted data, for example, maps the user side data into a corresponding MPLS tunnel according to information such as Virtual Local Area Network (VLAN) and 802.1p priority level in the extracted data.
In the implementation of the present invention, the inventors find at least the following problems in the prior art.
1) GPON technologies are not associated with MPLS technologies, and although accessing a network through the GPON, the OLT is further required to map the user side data into the MPLS tunnel through Ethernet after terminating the GPON.
2) Since the mapping between the user side data and the MPLS tunnel can only be performed through the Ethernet, the mapping is somewhat limited by the Ethernet itself, for example, when a plurality of operators shares the same OLT, VLANs of different operators are required to be uniformly planned; otherwise, the OLT cannot map the user side data into the MPLS tunnel according to the VLAN. However, the uniform planning of VLANs of different operators causes a limited capacity and poor flexibility of the service configuration.